江宁台地电场地地铁干扰试验结果分析

Testing Results of Subway Interferences to the Jiangning Electromagnetic Observation Site

城市地铁建设对周围电磁观测造成了很大的影响,地电阻率场地需要避让地铁的距离为25公里以上,给存在地铁干扰的场地搬迁选址造成了很大的困扰。本文针对南京地铁的影响进行了试验,分析试验结果对江宁台地电场地原址重建提出了新的布极方案,该方案采用缩短供电极距来抑制地铁干扰,采用深埋电极来保证探测深度和抑制表层影响。为受地铁影响而不采取避让措施下地电场地的选择提供了新的思路。

City subway construction can cause great impacts on the surrounding electro- magnetic observations, and geoelectrical resistivity field must have a distance above 25 kilometers to avoid subway interferrence, causing a lot of trouble to the relocation of field. In this paper, effects of the Nanjing subway is tested, the new arrangement of electrodes scheme is put forward to the relocation of Jiangning site. This scheme adopts shortening the current distance to suppress the subway interference, using deeply buried electrode to guarantee the detection depth and suppress the surface effect. The new ideas are provided to choose the electric field which has been affected by subway while not taking the avoiding measures.